Circuit interrupters



Sept. 14, 1965 J. E. HARDER 3,206,570

CIRCUIT INTERRUPTERS Filed Sept. 19, 1961 4 Sheets-Sheet 1 Fig.l.

WITNESSES INVENTOR John E. H urder P 4, 1965 J. E. HARDER 3,206,570

CIRCUIT INTERRUPTERS Filed Sept. 19, 1961 4 Sheets-Sheet 2 p 14, 1965 .1. E. HARDER 3,206,570

CIRCUIT INTERRUPTERS Filed Sept. 19, 1961 4 Sheets-Sheet 3 Sept- 1965 J. E. HARDER CIRCUIT INTERRUPTERS 4 Sheets-Sheet 4 Filed Sept. 19. 1961 United States ?atent O 3,206,570 CER CUIT ENTERRUPTER John E. Harder, Richland Township, Monroe County, lnrh, assignor to Westinghouse Electric Corporation, East Pittsburgh, Pin, a corporation of Pennsylvania Filed Sept. 19, 1961, Ser. No. 139,tli4 3 (Ilaims. (Cl. mil-62) This invention relates, generally, to circuit interrupters and, more particularly, to operating mechanisms therefor.

It is an object of this invention to provide a novel operating mechanism for effecting snap operation of contacts in a circuit interrupter.

It is another object of this invention to provide a novel operating mechanism for effecting snap operation of circuit interrupter contacts independently of the speed of action of the operating handle for the operating mechanism.

It is yet another object of this invention to provide a contact operating mechanism for effecting operation of the contacts in a trip free sectionalizing mode in response to a sectionalizer counter mechanism and to provide a snap operation of the contacts in a switching mode in response to operation of an operating handle.

A further object of this invention is to provide within a sealed tank an operating mechanism for effecting snap operation of contacts in the tank by means of a mechanism operable externally of the tank and extending through a sealed aperture in the tank wall and requiring only a minimum motion of the mechanism, thus facilitating effective sealing of the tank by bellows means connected to the tank and the mechanism.

These and other objects will be better understood from the following description taken in conjunction with the accompanying drawings, wherein:

FIGURE 1 is a sectional view of a gas-filled line seetionalizer embodying the principal features of the invention;

FIG. 2 is a bottom plan view of a portion of the sectionalizer of FIG. 1 showing the handle operating mech anism thereof;

FIG. 3 is a side elevational view of the operating mechanism of the line sectionalizer of FIG. 1;

FIG. 4 is an elevational view of the opposite side of the operating mechanism of FIG. 3;

FIG. 5 is a top plan view of the operating mechanism of FIG. 3;

FIG. 6 is a sectional view of the operating mechanism of FIG. 3;

FIG. 7 is a sectional view of the operating mechanism of FIG. 3 showing the operating mechanism in the collapsed position;

FIG. 8 is a sectional view of the operating mechanism taken along the lines VIllViII of FIG. 6 and showing the latch mechanism thereof; and,

FIG. 9 is a side elevational view of a modification of the operating mechanism.

The operating mechanism comprising this invention is intended primarily for use in a gas-filled high capacity automatic line sectionalizer 16 as shown in FIG. 1 of the drawings.

Generally, the sectionalizer Ill comprises a pressure vessel or tank 11 having an externally mounted operating handle mechanism 12 at the bottom thereof, and a pair of bushings 13 (only one shown) projecting from the top thereof.

The tank 11 is completely hermetically sealed to contain therein sulfur hexafluoride gas.

The use of a gas, particularly sulfur hexafiuoride, contribute several major advantages.

For many applications, especially those where the life of the interrupting medium has been a determining factor, maintenance can be reduced. Electrical grade oil, the medium heretofore used in automatic line sectionalizers, suffers deterioration from two primary causes. Arcing in the oil causes carbonization of the oil and an irreversible liberation of quantities of gas. This liberation of gas makes it necessary to vent the device to the outside air to prevent pressure buildup. The very presence of this vent allows breathing which can be accompanied by condensation and a buildup of water in the oil.

Sulfur hexafluoride is relatively stable in the presence of the arc. The are products themselves have excellent dielectric characteristics and the net pressure change from arcing, if any, will be a very slight reduction in pressure. By sealing the gas in the container any contamination from breathing is eliminated. Thus, for installations where the maintenance cycle is determined by the life of the interrupting medium, the use of sulfur hexafluoride gas may increase the time before maintenance is required.

The use of sulfur hexafiuoride instead of oil will eliminate any fire hazard and considerably reduce the explosion hazard. Sulfur hexafluoride will not burn or support combustion. In the event of electrical failure, pressure buildup is reduced by the relatively large gas volume in the gas filled device compared to the relatively small air space in the oil filled deivce.

The use of the gas also contributes uniform operation regardless of ambient temperature, the friction forces of the gaseous medium being small compared to those of a liquid medium.

Continuing with the general description of the sectionalizer 16 an operating mechanism 14 is connected to operate a contact mechanism 15 in a sectionalizing mode in response to the operation of an integrator mechanism 16 or in a circuit switching mode in response to the operation of the previously mentioned handle mechanism 12.

The integrator 16 and its associated solenoid 17 for operating the integrator in response to line deenergizations after fault current, is fully disclosed and claimed in copending application Serial No. 139,195, filed September 19, 1961, by A. R. Harm and W. D. Wagner and assigned to the same assignee as the present application which issued December 10, 1963, as US. Patent No. 3,114,021.

The present invention relates to the aforementioned operating mechanism 14, shown in detail in FIGS. Q through 9.

In one application of the present invention, the heart of the operating mechanism is a flexible means comprising a lever system, which includes a pair of levers pivotally connected to each other and biased into predetermined normal position with respect to said pivot by means of a spring mechanism carried by the lever system. The lever system is pivoted at one end for movement of the free end from either one of a pair of spaced latch means to the other, each latch means being engageable with the free end to hold the lever in the corresponding latch position. An operating handle is connected to one of the levers of the lever system near the pivot point to rotate the lever system about the pivot against the holding force of one or the other of the latch means to break the lever system from the normal position, thus charging the spring and at the same time changing the effective length of the lever system to effect release of the lever system from the latch by sliding disengagement whereupon the charged spring snaps the other lever into alignment with the pivot lever to effect snap action of movable contact means connected to the free end of the pivoted levers, and to propel the free end of the lever system into latched engagement with the other latch means. Thereafter, operation of the handle means in the opposite direction effects reverse action of the lever system to the other latch to effect reverse snap action of the movable contact means.

The operating mechanism as described may include an optional auxiliary biasing system for rotating the lever system from one latch device to the other to effect opening movement of the movable contacts. When this system is utilized, the lever system may be counterweighted to provide for operation regardless of attitude with respect to gravity.

The connector means between the operating handle and the lever system may be connected to the lever system adjacent the prime pivot point, thus necessitating only a relatively short movement of the handle to effect a relatively large snap operating action of the lever system. This relatively short movement of the intermediate operating mechanism facilitates hermetic sealing of the operating mechanism in a tank by means of a reliable bellows system of relatively small movement.

Referring now to the drawings, particularly FIGS. 3, 4, 5 and 6, the operating mechanism 14 is seen to generally comprise a flexible means, which more specifically comprises a lever assembly 17, a latch assembly 18 for holding the lever assembly in its various positions, an intermediate or connecting operating mechanism 19 for operating the lever system 17 in response to operation of the handle system 12, a trip free latch mechanism 20 and an optional lever mechanism 21 for biasing the lever system 17 to open the contacts in response to a sectionalizing command.

The operating mechanism 14 is mounted between a pair of mounting plates 24, 25 which are relatively fixed in spaced parallel relationship by means of suitable nut, bolt and spacer assemblies 26, 27, 28 and 201.

The lever assembly 17 comprises a pair of pivotally connected operating levers 34, biased into alignment by means of a spring biasing mechanism 36 carried by the levers 34 and 35.

The operating lever 34 is pivotally mounted between the plates 24- and 25 on a pivot pin 37 extending through the lever 34 and plates 24, 25 with the ends of the pin 37 riding in a pair of opposing vertical slots 38, 39 in the plates 24 and 25, respectively. The lever 34 comprises a base portion 4-!) disposed on one side of the pivot pin 37, and a pair of spaced parallel opposed arm members 41, 42 extending on the other side of pivot pin 37. The base portion 40 may be enlarged to provide a counterweight for the entire lever system as hereinafter described.

The aforementioned operating Y-shaped member having at one end a pair of spaced parallel arms 45, 46 overlapping the ends of arms 41, 42 of lever 34, and pivotally attached to arms 41, 42 by means of a pin 47 extending through both pairs of arms. The other end of lever 35 comprises a single bar coextensive with the axis of the parallel arms and riding freely between the guide plates 70 and 71 and engageable with the latch assembly 18 in a manner hereinafter described in detail.

The biasing mechanism 36 for normally aligning the levers 34, 35 on a common axis comprises a pair of keeper bars 48, 49 oppositely positioned on the top and bottom of the overlapping portions of arms 41, 42, 45 and 46 of the levers 34 and 35, and extending transversely thereof. The keeper bar 48 is supported in this position by means of a pair of links 50, 51 each having one end pivotally attached to an end of bar 48, and each having the other end pivotally attached to the previously described pivot pin 47. The keeper bar 49 on the top of levers 34 and 35, as shown in FIG. 5, is supported in this position by means of a pair of links 52, 53, each having one end pivotally attached to an end of keeper 49 and each having the other end pivotally attached to the reviously described pivot pin 47.

The upper keeper bar 49 has centrally attached thereto a centrally apertured spring keeper 58, with the aperture extending through the keeper 58 and bar 49. The lower arm 35 comprises a keeper bar 48 has centrally attached perpendicularly thereto an elongated rod 59 extending through the aperture in keeper 58 and bar 4) in reciprocal slidable relationship therewith. A second spring keeper 60 is attached to the upper end of rod 59 in any suitable manner. A suitable compression spring 61 encircles the rod 59 between the spring keepers 58 and 68', thus biasing keeper bars 48 and 49 toward one another to bias the levers 34 and 35 into alignment as shown in full lines in FIG. 5.

From the foregoing, it will be apparent that should a force be applied to misalign or buckle or collapse levers 3 35 relative to pivot 47, the keeper bars 48 and 49 are spread apart, compressing spring at and increasing the biasing force tending to quickly realign the levers 34 and 35 when the buckling force is discontinued.

The latching mechanism 18 is provided to latch the lever assembly 17 in either the upper contact closing position, as shown in FIG. 6, or in the lower contact opening position, as hereinafter described. The intermediate operating mechanism 19 applies force to the lever mechanism 17 and cooperates with the latch mechanism 18 to effect buckling or collapsing of the lever system 17, as shown in broken lines in FIG. 6, and in full lines in FIG. 7; whereby the effective distance between the pivot 3'7 and the free end of lever 35 is effectively shortened as the lever system 17 buckles in response to the rotation of lever 34 about pivot 37. It is seen that the free end of lever 35 is normally held by latch mechanism 18 against the buckling force of the operating mechanism 19 whereupon the lever system 17 buckles about pivot 47 thus effectively shortening the length of the lever system 17 so that the lever 35 moves to the left and is ultimately released from the latch means 18, whercafter the spring biasing means 36 effects realignment of levers 35 and 34 with a snapping action, thus effecting snap operation of the contact mechanism connected to the free end of lever 35.

Referring to FIGS. 1 and 6, it will be observed that the contact mechanism 15 includes movable contacts 62 connected to the end of a movable contact control member 63 which is pivotally attached to the free end of lever 35 of the lever system 17 by means of pivot pin 64.

From the foregoing it is seen that the upper position of the lever system 17, as shown in FIG. 6, constitutes a closed contact position, while the lower position of lever system 17, as hereinafter described constitutes an open contact position.

The latch mechanism 13 for latching the lever system 17 in either the upper, contact closed, position or the lower, contact open, position is disclosed generally in FIG. 6 and is shown in more detail in FIG. 8. The latch mechanism generally comprises a pair of latching devices 68, 69 spaced along the path of the free end of lever 35 of the lever system 17, with the latch device 68 holding the lever system 17 in the upper, contact closed, position and with the latch device 69 holding the lever system 17 in the lower, contact open, position.

The latching devices 68, 6% of latching mechanism 18 are supported with respect to support plates 24 and 25 by means of a pair of guide plates 79, 71. The guide plates 7t), 71 are spaced in parallel relationship substantially midway between the support plates 24, 25 in separate planes parallel and adjacent to the plane of travel of the lever 35, whereby the lever 35 in its movement from the upper to the lower position, and vice versa, is guided between the plates '79, 71. The guide plates 79, 71 are fixed in the described position by means of the previously described connecting bolts 26, 27 and by means of spacer elements '72, 73 and 74 sleeved on bolt 27 and by means of spacers 75, 76 and 77 sleeved on bolt 26.

The lower latch device 69 of latch member 18 comprises a latch support element 83, a trigger 84 mounted therein, and a spring 85 biasing the latch into the path of lever 35. The latch support 83 is basically a U-shapcd plate member having a pair of side walls 86, 87 connected at one end by means of a base member 88. The base member 88 extends through a suitable aperture in plate and the free ends of the side wall members 86, 87 extend through a suitable aperture in guide plate 71. The side walls 86, 87 are each provided with a pair of opposed lateral extensions 89, 99, extending the full distance between the guide plate 71 and support plate 25, thus fixing the support 83 with respect thereto. The base portion 88 is provided with an aperture 97 cooperating with laterally opposed slots 98, 99 in side walls 86, 87, respectively, extending inwardly from the free end of the side walls 86, 87 and adapted to receive trigger 84. The trigger 84 comprises a body portion 101) extending through aperture 97, and a head portion 101 on the inner end thereof. The head portion 101 includes a pair of laterally extending oppositely disposed lugs 102, 193 slidably riding in the slots 98, 1 9, respectively. The head portion 101 is tapered at its free extremity, as at 104 so as to provide a striking surface obliquely arranged in the path of the lever whereby the striking of the surface by the lever 35 as it moves away from the upper latch position will provide a suitable force urging the trigger 84 in an axial direction as guided by slots 98, 99 and aperture 97 in support 83. The compression spring encircles the trigger body and is compressed between the head portion 1111 and the inside of base portion 88 as the trigger is axially displaced when struck by the lever 35, thus biasing the trigger 85 into the path of lever 35 after lever 35 passes by in a manner hereinafter described, whereupon the lever 35 and lever system 17 is latched in the lower, contact open, position.

The upper trigger device 68 is basically similar to the above-described trigger device 69, and comprises a latch support element 109, a trigger 111) mounted therein, and a spring assembly 111 biasing the latch into the path of lever 35. The latch support 1% is a U-shaped plate member having a pair of side walls 112, 113 connected at one end by a base member 114. The base member 114 extends through a suitable aperture in plate 24, and the free ends of the side wall members 112, 113 extend through a suitable aperture in guide plate 70. The side walls are each provided with a pair of laterally opposed extensions 115, 116 and 117, 118, respectively, in the plane of the side Walls, and extending the full distance between the guide plates 70 and plate 24, thus fixing the support 109 with respect thereto. The base portion 114 is provided with a slot 119 extending downwardly from the top edge thereto to a point substantially in the center of the base. The slot 119 is disposed to cooperate with a pair of laterally disposed slots 120, 121 in side walls 112, 113, respectively, extending inwardly from the free end of the side walls and adapted to receive the trigger 111?. The trigger 111 comprises a body member 122 riding perpendicularly with respect to the slot 119 and normally riding on the bottom of slot 119, and includes a head portion 124 at an end thereof. The head portion thereof includes a pair of laterally extending, oppositely disposed lugs 128, 129 slidably riding in slots 120, 121, respectively. The head portion 124 is tapered at its free extremity, as at 130 so as to provide a surface obliquely arranged in the path of the lever 35 whereby the striking of the surface by the lever 35 as it moves away from the lower latch portion 6? will provide a suitable force urging trigger 110 in an axial direction as guided by the slots 120, 121, and 119 in support plate 109.

The spring device 111 for biasing the trigger into the path of the lever 35 comprises a torsion spring 131 and a spring support 132. The spring support 132 comprises a base member 133 attached to the inner side of support plate 24 below the upper trigger assembly 68 by means of internal tab 134 and a screw 135. The torsion spring 131 is fixed to the base 133 by means of a screw 137 holding an end of the spring to the base 133, with the axis of the spring 131 disposed perpendicularly with respect to the axis of the trigger 122 and with the other end of spring 131 extending upwardly and attached to a tab 137 on the underside of trigger head 124.

From the foregoing description of the upper trigger assembly 69 and the lower trigger assembly 68, it is seen that both triggers are spring biased into the path of lever 35 to normally prevent passage of the lever 35 and to latch the lever in the operating position after passage.

It is to be noted that the slot 119 in the base 114 of the upper trigger assembly 68 and the spring 131 provides also for rotation of the trigger 122 about the lugs 128, 129 to provide trigger release operation in response to a sectionalizing command, as will be hereinafter described in detail.

The intermediate operating mechanism 19 comprises a shaft member 141 connecting the lever system 17 to the handle mechanism 12, externally of the tank 11, and a bellows member 142 effecting a seal between the shaft 141 and the tank 11 to maintain hermetic sealing of the tank 11, as previously described. The upper end of shaft 141 extends vertically between the arms 41, 42 of lever 34 and is pivotally attached thereto by means of a pin 143 extending transversely of the lever 34 through the arms 41, 42 at a point between the previously described pin 37 and pin 47 and through a pair of vertically disposed -slots 144, 145 in support plates 24, 25, respectively. The lower end of shaft 141 extends through an aperture 146 in the tank wall 11 for external connection to the operating handle mechanism 12, as hereinafter described in detail.

The bellows mechanism 142 surrounds the shaft 141 at its lower end and is sealed at the upper end of the bellows to the intermediate portion of shaft 141 by any suitable means, such as welding. The lower end of the bellows includes an extension 147 extending through aperture 146 and fixed in sealed relationship therewith by any suitable means such as welding, thus connecting a peripheral flange 148 on the extension 147 to the wall 11. If desired, the extension 147 may be additionally connected in sealed relationship with the tank wall by means of a hose clamp and rubber boot, not shown, on that portion of the extension externally of the tank wall 11 to protect the inside of the bellows. The bellows provides hermetic sealing of the tank and at the ame time provides for free reciprocal motion of the shaft member 141 for operation of the lever system 1'7.

In order to pnovide a lower limit of movement of the lever system 17, there is provided a stop member 149 disposed between the support plates 24, 25 and including axial extensions 153, 154 on opposite ends of the stop 14?, A suitable bumper 155, which may be comprised of resilient material, may be 'aflixed in any suitable manner to the top side of the intermediate portion of the stop body 149 to absorb the impact. A metallic plate (not shown) may overlie the bumper 155 to distribute impact.

In describing the operation of the operating mechanism as thus far described, it will be assumed that the lever system 17 is in the contact closed position, as illustrated in FIG. 6, in which position the spring biasing mechanism 36 holds the levers 34, 35 in the aligned condition with the outer end of lever 35 resting atop trigger 122 in upper trigger assembly 68, thus holding the contacts 15 in the closed position. If new a force is applied to the operating shaft 141 externally of the tank 11 to pull the shaft 141 in a downward direction, a moment of force is applied to lever 34 to rotate the lever system 17 clockwise about pivot 37. Since the free end of lever 35 is initially positioned atop trigger 122, the levers 34 and 35 buckle or collapse about connecting pivot 47, thus spreading keepers 48, 49 in the spring biasing assembly 36, gradually compressing spring 61 and storing energy therein as the lever 34 continues to rotate about pivot 37. As the levers 34, 35 buckle, the effective length of the levers 34, 35 is shortened, moving the end of lever 35 to the left toward a drop'oif position with respect to trigger 122. The condition of the lever system just before the lever 35 slides from atop trigger 122 is generally illustrated in broken lines FIG. 6 and in full lines in FIG. 7 showing the lever 34 substantially fully rotated to the downward position where pin 143 is substantially at the bottom of slot 144, and with the spring assembly 36 substantially fully charged. Further downward movement of shaft 141 from the position shown in FIG. 1 efiects release of the free end of lever 35 from ato trigger 122, thus eliminating the restraining force holding the lever system 17 in the buckled position whereupon it will be understood that the spring assembly 36 discharges its energy to effect a snap realignment of lever 35 with lever 34, the latter now being in the down position, thus effecting a snap opening operation of contact assembly 15. As the free end of lever 35 travels rapidly in a downward direction, it strikes the striking surface 104 of trigger 101) in the lower trigger assembly 69 whereupon trigger 11H) moves axially out of the path of lever 35 against the bias of trigger spring 85, permitting passage of the free end of lever 35 which ultimately strikes stop 149. The trigger 19!) returns to its normal position across the path of lever 35 under the force of spring 85 to retain the lever system in the lower contact opening position so that an upward movement of shaft 141 will provide the same snap action of the lever system 17 toward the contact closing position as initially described. In the contact closing operation, upper trigger assembly 68 operates as does the lower trigger assembly 69, as'described above, with the trigger 122 moving axially out of the path of lever 35 against the bias of torsion spring. 131, and thereafter returning to its normal position to latch the free end of lever 35 in the contact closing position.

From the foregoing, it is to be noted that only a relatively small reciprocal movement of shaft 141 is required to effect a relatively large snap action of the lever system 17.

The handle assembly 12 for operating the intermediate operating assembly 19, externally of the tank 11 is shown in FIGS. 1 and 2 and comprises a support 155 and an operating lever 156. The support 155 is a frame member including a pair of side walls 158, 159, a partial bottom wall 160 and an end wall 161. The side walls 158, 159 are welded to the bottom of tank 11. The handle 156 is an elongated bar member having a bifurcated end portion comprising a pair of arms 166, 167 straddling the lower end of bar 141 and attached thereto by means of a pivot pin 168 extending through the arms 166, 167 and a lower end of shaft 141. The bifurcated end of handle 156 is pivotally supported within the support 155 by means of a pin 169 extending laterally through the arms 166, 167 and pivotally mounted through the side walls 158, 159. As described above, only a small reciprocal movement of the shaft 141 is required to operate the lever system 17. Accordingly, the pins 168 and 169 may be mounted relatively close together for providing a small travel of pin 168 about pivot pin 169 as the handle 156 is raised or lowered. The extended length of the handle 156 provides an ample lever arm for providing adequate force to operate the shaft 141 and lever system 17 and at the same time, provides an outward visible indication of the operating position of the operating mechanism within the tank 11. A loop 171 is provided at the free end of handle 156 for convenient gripping by the operator.

In order to eifect sectionalizing operation of the operating system 14 in response to operation of the integrator device generally indicated at 16 in FIG. 1, the previously described upper trigger assembly 68 is caused to operate in a sectionalizing mode to effect release of the lever system 17 in a manner different from that described above.

Referring to FIGS. 3 and 8 to show the manner in which the upper trigger assembly 65 is operated in a sectionalizing mode, there is illustrated a trip device 172 responsive to the output of the integrating device disclosed and claimed in the previously mentioned copcnding application Serial No. 139,195.

As described in the copcnding application, the trip assembly 172 comprises a trip bar 173 operable for movement along its axis in response to the operation of a counting device in the integrator, which device counts a predetermined number of circuit interruptions in the line, each interruption of the line can be considered as being effected by a reclosing device in series with the sectionalizer and each interruption occurring after a fault current has been detected. The trip bar 173 moves from the normal position, as shown in FIG. 3 to the left to effect operation of the upper trigger assembly 68, as will now be described.

At the left end of the trip bar 173 of the integrator 16, as shown in FIG. 3, there is provided a pair of rollers 174 mounted upon support plate 24 in any suitable manner and disposed to guide therebetween the bar 173 in its axial movement. The other end of bar 173 is pivotally attached to one end of a pivot lever 175 by means of pin 176, the other end of the pivot lever 175 being pivotally attached to support plate 24 by means of a pivot pin 177. A latch lever 173 is fixedly attached to pivot lever 175 and includes at the upper end thereof a laterally extending latch member 179 crossing over lever 175 and normally overlying the protruding end of trigger 122 in the previously described latch device 68. Lever 178 is biased into the normal position, as shown in FIG. 3, by means of a spring mechanism, not shown.

In describing the operation of the operating mechanism 14in a sectionalizing mode, it will be understood that the lever system 17 is latched in the upper contact closing position, as in FIGS. 6 and 8 with the lever 35 latched against the trigger assembly 68 in the manner previously described with respect to the operation of the operating mechanism in a switching mode, and with the trip bar in the normal position shown in FIG. 3. When the integrator 16 operates to move trip bar 173 to the left in FIG. 3, lever 175 moves counterclockwise about pivot 177, thus rotating latch lever 178 and latch 179 counterclockwise about pivot 177 so as to elfect release of trigger 122. When trigger 122 is released, the now unopposed weight of lever 35 on the upper side of trigger head 124 effects clockwise rotation of trigger 122 about lugs 128, 129 on the head 124 and against the bias of spring 131 thus removing the trigger from the path of lever 35 and permitting the entire toggle lever system 17 to drop as a unit to the contact open position in latching engagement with lower trigger assembly 69 in the manner previously described. After the lever 35 passes below trigger assembly 68, the spring 131 biases the trigger 122 counterclockwise to the normal position, as shown in FIG. 8. Resetting of the sectionalizer mechanism 16, as described in the aforementioned copcnding applicaton, effects axial movement of the trigger bar 173 to its normal trigger latching position as shown in FIG. 3.

From the foregoing description of operation of the operating mechanism 14 in a sectionalizing mode, it is to be noted that operation of the lever system 17 is not a snap action as described in the operation of the mechanism in a switching mode. Inasmuch as sectionalizing operation of the contacts 15 occurs during a period of no current condition in the ilne, as is usually the case in sectionalizers generally, no arcing will occur, and fast contact separation of a snap action type is not required. However, reclosing of the contacts after sectionalizing operation is effected by manual operation of the operating mechanism 14, as previously described, thus effecting a snap closing operation.

The foregoing description of the operation of the operating mechanism 14 in a sectionalizing mode, as cffected by the weight of the toggle lever system 17, is based upon the assumption that the lever 17 is not counterweighted and that the operating means 14 is so disposed with respect to gravity to provide clockwise motion of lever 17 when the trigger 122 is operated in a sectionalizing mode. However, in order to provide for sectionalizer operation of the operating mechanism regardless of the attitude of the mechanism with respect to gravity, the lever system 17 is provided with a previously mentioned counterweight 40, and there is also provided an additional biasing mechanism 21, shown in FIG. 4, for biasing the lever system 17, as an entity, from the contact closing position to the contact opening position, in cooperation with an additional biasing mechanism 179 for biasing the intermediate operating mechanism 19 to the contact opening position.

The biasing mechanisms 21 and 179 are located on opposite sides of the operating mechanism 14 externally of the support plates 24 and 25 to bias the previously mentioned pin 143 in a downward direction, thus rotating lever system 17 clockwise about pin 37 and lowering the shaft 141 of the intermediate operating mechanism 19.

The biasing system 21, FIG. 4, comprises a lever 18% disposed adjacent the outside of support plate 25 and pivotally attached at pivot point 131 to the end of pivot 37 of the toggle lever system 17 extending through slot 39 in plate 25. The lever 180 includes an inwardly extending flange portion 182 spaced from the pivot point 181 for over-riding pin 143 to force the pin 143 downwardly about pin 37. A stretched spring 186 is attached at one end to the upper end of lever 18d and at the other end to a spring mount 187 disposed on the outside of support plate 25 later-ally adjacent the trigger assembly 18, thus providing a counterclockwise biasing force on ever 181) in FIG. 4, which biasing force is viewed as a clockwise rotation in FIG. 6 to push pin 143 downwardly in slot 145 to rotate the lever system 17 clockwise in FIG. 6 when the trigger assembly 58 is operated in a sectionalizing mode as previously described. An auxiliary spring 188 is attached at one end to a pivot point '187 on lever 180 displaced from pivot point 131, and is stretched downwardly for attachment at the other end to a connecting pivot point 1% on a mounting bar 191 fixedly attached to the outside of support plate 25 by means of a bolt and nut 192. Spring 18% provides a downward component of force on lever 180 to cooperate in a manner hereinafter described with biasing system 179 to axially lower the shaft 141 and compress the bellows 142 during a sectionalizing operation.

The biasing system 179, FIG. 3, is disposed on the outside of support plate 24 and comprises a lever 192 pivotally attached at one end to the outer end of pivot 37, and including at the other end an inwardly extending tab 193 over-riding the end of pin 143. A spring 194 is attached at the upper end to the lever 192 at a pivot point 195, and is stretched downwardly and attached at its lower end to point 196 on mounting bar 2110, which bar is fixedly attached to support plate 24 by means of bolt and nut 2111. It will be observed that spring 194 in biasing means 179, and spring 188 in biasing means 21, cooperate to actually move the pivot pin 143 and the shaft 141 in the operating means 19 downwardly when the upper trigger assembly 68 is operated in a sectionalizing mode. Also the positive gas pressure inside of tank 11 causes a net compressing force on bellows 142 biasing operating rod 141 toward the open contact position.

The trip free mechanism 20 shown in FIG. 6, provides for assuring operation of the toggle lever system 17 in a sectionalizing mode even though an operator should be operating the handle mechanism 12 in an attempt to effect a contact closing operation of the toggle system 17 during a sectionalizing operation.

The trip free mechanism 2d includes a latch member 202 fixedly attached at the upper end to shaft 203 disposed transversely of lever arm 34 and disposed above pivot 37, the shaft 203 having its ends extending through opposed apertures in support plates 24 and 25 whereby the latch 202 is normally disposed in a vertical condition for engaging the pivot 37 between the lever arms 41, 42 of lever 34 to hold pin 37 to the bottom of slots 38, 39 in support plates 24, 25, respectively. Integral spacers 204, 295 are provided on the shaft 203 between the latch 2112 and the inside walls of support plates 24 and 25 to maintain the latch 202 positioned between arms 41, 42. The end of the shaft 203 extending through support plate 24 is provided with a crank pin 206 fixedly mounted transversely through the pin and extending downwardly through an aperture 267 in the previously described trip bar 172 as operated by the integrator mechanism 16.

In describing the operation of the trip free latch mechanism 211, it will be assumed the latching device 202 is in the normal position shown in FIGS. 3 and 5, with the trip bar 172 in the normal position, and with the latch 292 engaging the pin 37 to hold the pin in the bottom of slot 38. Under these conditions, the pin 37 may not move upwardly in the slot 38 so that operation of the handle mechanism 12, as hereinbefore described, to effect switching of the lever system 17, occurs in the manner previously described. As previously described, if the lever system 17 is to be closed, shaft 141 is moved upwardly to close the contacts by providing a counterclockwise moment of force on lever arm 34 about the normally fixed pivot pin 37 to effect normal closing operation of the lever system 17. A sectionalizing operation cannot occur except with the contacts closed. The trip free feature is to allow sectionalizing if the handle is being held in the closed position. In the closed position, lever 2112 is above but not quite touching pin 37. In the event that a sectionalizing signal occurs-while the handle is being held in the closed position, trip bar 173 moves lever 202 out of the way of pin 37 just before trigger pin 122 is released by tab 17 9, thus allowing lever system 17 to rotate about pin 143 to the open contact position.

FIG. 9 relates to a modification of the flexible lever system 17 of FIGS. 3 through 7 and comprises a single lever 211 having inherent flexible characteristics, such as a leaf spring. One end of the spring 211 is attached to a fixed pivot 212, while the other end is free for movement between a pair of trigger mechanisms 213, 214 which may be of the type described above and identified as trigger assemblies 68 and 69. A stop device 215 is provided adjacent the lower trigger assembly 214 for limiting downward motion of lever 211. An operating member 216 is pivotally connected to an intermediate portion of spring 211 near pivot 212 and is axially operable to effect operation of lever 211 about pivot 212. When operating member 216 is pulled downwardly, spring 211 flexes downwardly to gradually store energy in the flexed spring and to pull the free end of spring 211 slidably ofi trigger 213, whereafter the free end of spring 211 snaps into normal axial alignment with the pivoted end of spring 211 to effect snap operation of the contacts 217 attached to the free end of spring 211.

From the foregoing, it is apparent that the present invention provides in a circuit interrupter, an operating mechanism including a novel lever system comprising flexible means responsive to a relatively small control movement to provide a relatively large snap operation of contacts. It is also apparent that there is provided an operating mechanism operable in a switching mode to etfect snap operation of contacts, and which is also operable in response to a sectionalizing command to provide sectionalizing operation of the contacts with trip free action. It is further apparent that the short stroke requirements of the operating mechanism ideally adapt the same for mounting within a hermetically sealed tank in combination with a bellows mechanism sealing the operating mechanism to the tank wall.

While there has been shown and described certain preferred embodiments of this invention, it will be obvious to those skilled in the art that it is not so limited but is susceptible of various changes and modifications without departing from the spirit and scope thereof.

1 claim as my invention:

1. An operating mechansim for separable electrical contacts, comprising: a support means; elongated flexible means having one end attached to a pivot and the other end adaptedfor connection to a movable contact means in a line circuit; said pivot being movable transversely of its axis in guide means on said support; said guide means having an upper and lower limit; first latch means on said support normally holding said pivot at the lower limit of said guide means and operable to release said pivot; operating means including an operating member attached to said elongated means to provide a force on said elongated means in a direction substantially parallel to the line of motion of said pivot in said guide means; said operating member being operable to selectively rotate said elongated means about said pivot from either one of an upper or lower spaced position at one side of said pivot along said path to the other spaced position to effect opening and closing operations, respectively, of said contact means in a switching mode; latch means at each of said upper and lower spaced positions and including holding means normally preventing movement of said elongated means until a predetermined force has been applied to the elongated means by the operating member to urge the free end of the elongated means to the other position in a snap movement in both directions between said positions; the holding means in the upper latch means being operable to release the free end of the elongated means; said latch means and said holding means in the contact closed position and said first mentioned latchaing means being simultaneously operable in response to a predetermined condition in the line circuit whereby the pivot may move upwardly in the guide means in response to a con tact closing operation of the operating member to permit said elongated means to rotate and to effect an opening operation of said contacts.

2. A contact operating mechanism comprising support means, a first lever pivotally attached to said support means at a first pivot, a second lever having one end pivotally connected to said first lever at a second pivot spaced from said first pivot and having a free end rotatable between first and second positions and adapted for connection to a movable contact, said first and second positions corresponding to the open and closed positions of said movable contact, spring means connected to said levers to normally maintain said levers in aligned relation, said spring means being disposed to apply a biasing force substantially transversely of said levers when said levers are in aligned relation, and operating means connected to said first lever for rotating said first lever about said first pivot, first and second latch means disposed adjacent to the first and second positions of said free end of said second lever to en age and prevent rotation of said free end between said positions, said operating means being operable to rotate said first lever out of alignment with said second lever to thereby charge said spring means under compression and release the free end of said second lever from one of said latch means, said spring means being then operable to discharge and actuate said second lever into alignment with said first lever with a snap action and into engagement with the other latch means, said movable contact being movable with said second lever in both directions with a snap action, said first pivot being relatively movable to permit actuation of the free end of said second lever to said second position even though said operating member is being operated to rotate the free end of said second lever to the first position of said second lever.

3. An operating mechanism for separable electrical contacts, comprising: a support means; elongated flexible means having one end attached to a pivot and the other end adapted for connection to a movable contact means in a line circuit; said pivot being movable transversely of its axis in guide means on said support; said guide means raving an upper and lower limit and comprising one or more slots provided in said support means, first latch means on said support normally holding said pivot at the lower limit of said guide means and operable to release said pivot; operating means including an operating member attached to said elongated means to provide a force on said elongated means in a direction substantially parallel to the line of motion of said pivot in said guide means; said operating member being operable to selectively rotate said elongated means about said pivot from either one of an upper or lower spaced position at one side of said pivot along said path to the other spaced position to effect opening and closing operations, respectively, of said contact means in a switching mode; latch means at each of said two positions and including holding means normally preventing movement of said elongated means until a predetermined force has been applied to the elongated means by the operating member to urge the free end of the elongated means to the other position in a snap movement in both directions between said positions; the holding means in the upper latch means being operable to release the free end of the elongated means; said latch means and said holding means in the contact closed position and said first mentioned latching means being simultaneously operable in response to a predetermined condition in the line circuit whereby the pivot may move upwardly in the guide means in response to a contact closing operation of the operating member.

References Cited by the Examiner UNITED STATES PATENTS 2,725,446 11/55 Slepian 200--l68 X 2,783,322 2/57 Samuel et al. 20062 2,840,671 6/58 Gietfers 20062 X BERNARD A. GZLHEANY, Primary Examiner.

ROBERT K. SCHAEFER, Examiner. 

1. AN OPERATING MECHANISM FOR SEPARABLE ELECTRICAL CONTACTS, COMPRISING: A SUPPORT MEANS; ELONGATED FLEXIBLE MEANS HAVING ONE END ATTACHED TO A PIVOT AND THE OTHER END ADAPTED FOR CONNECTION TO A MOVABLE CONTACT MEANS IN A LINE CIRCUIT; SAID PIVOT BEING MOVABLE CONTACT MEANS ITS AXIS IN GUIDE MEANS ON SAID SUPPORT; SAID GUIDE MEANS HAVING AN UPPER AND LOWER LIMIT; FIRST LATCH MEANS ON SAID SUPPORT NORMALLY HOLDING SAID PIVOT AT THE LOWER LIMIT OF SAID GUIDE MEANS AND OPERABLE TO RELEASE SAID PIVOT; OPERATING MEANS INCLUDING AN OPERATING MEMBER ATTACHED TO SAID ELONGATED MEANS TO PROVIDE A FORCE ON SAID ELONGATED MEANS IN A DIRECTION SUBSTANTIALLY PARALLEL TO THE LINE OF MOTION OF SAID PIVOT IN SAID GUIDE MEANS; SAID OPERATING MEMBER BEING OPERABLE TO SELECTIVELY ROTATE SAID ELONGATED MEANS ABOUT SAID PIVOT FROM EITHER ONE OF AN UPPER OR LOWER SPACED POSITION AT ONE SIDE OF SAID PIVOT ALONG SAID PATH TO THE OTHER SPACED POSITION TO EFFET OPENING AND CLOSING OPERATIONS, RESPECTIVELY, OF SAID CONTACT MEANS IN A SWITCHING MODE; LATCH MEANS AT EACH OF SAID UPPER AND LOWER SPACED POSITIONS AND INCLUDING HOLDING MEANS NORMALLY PREVENTING MOVEMENT OF SAID ELONGATED MEANS UNTIL A PREDETERMINED FORCE HAS BEEN APPLIED TO THE ELONGAED MEANS BY THE OPERATING MEMBER TO URGE THE FREE END OF THE ELONGATED MEANS TO THE OTHER POSITION IN A SNAP MOVEMENT IN BOTH DIRECTIONS BETWEEN SAID POSITIONS; THE HOLDING MEANS IN THE UPPER LATCH MEANS BEING OPERABLE TO RELEASE THE FREE END OF THE ELONGATED MEANS; SAID LATCH MEANS AND SAID HOLDING MEANS IN THE CONTACT CLOSED POSITION AND SAI FIRST MENTIONED LATCHING MEANS BEING SIMULTANEOUSLY OPERABLE IN RESPOONSE TO A PREDETERMINED CONDITION IN THE LINE CIRCUITWHEREBY THE PIVOT MAY MOVE UPWARDLY IN THER GUIDE MEANS IN RESPONSE TO A CONTACT CLOSING OPERATION OF THE OPERATING MEMBER TO PERMIT SAID ELONGATED MEANS TO ROTATE AND TO EFFECT AN OPENING OPERATION OF SAID CONTACTS. 